409 



stem-mothers hatch from winter eggs about the middle of February, 

 and mature about the time of full bloom. The second generation of 

 Aphids matures about the beginning of April. The spring forms feed 

 on the tender stems and later on the leaf and fruit petioles. Winged 

 forms appear during the second week in April and are found until July. 

 These migrate for the summer to various water-plants, such as Poly- 

 gonum, Typlia, Nymphea (water lily), Potamogeton (pond weed), and 

 Alisma (water plantain). Towards the end of October, autumn 

 migrants appear on the winter host, feeding on twigs and petioles. 

 After a development period of about 20 days, pairing takes place and 

 winter eggs are deposited in the axils of the buds of the following year. 

 As the stem-mothers hatch so early and feed at exposed points, control 

 should not be difficult should the species become of sufficient economic 

 importance. A description is given of the characteristics by which 

 the species may be recognized and a table shows the comparative 

 measurements of the various forms. 



Coleman (G. A.). The Development of the Motion Picture and its 

 Place in Educational Work. — Jl. Ecmi. Entom. Concord, N.H., x. 

 no. 3, June 1917, pp. 371-373. 



The value of the motion picture to the economic entomologist as an 

 educational factor is pointed out in this paper. By means of the 

 X-ray and the microscope, in connection with the motion picture 

 camera, the external and internal anatomy of every living thing can 

 be photographed and all muscular and other movements of animal 

 and plant life can be recorded and reproduced. The value of motion 

 introduced into a classroom lecture is obvious, while all lines of 

 scientific investigation and farm and orchard management can be 

 brought before the general public by means of a motor-driven machine 

 and a few hundred thousand feet of film. 



QuAYLE (H. J.). Some Comparisons of Coccus citricola and C. hespe- 

 ridum. — Jl. Econ. Entom., Concord, N.H., x, no. 3, June 1917, 

 pp. 373-376. 



This paper points out the differences between Coccus citricola and 

 C. hesperidum, which in former years have frequently been confused. 

 Besides the morphological differences, the life-histories and habits 

 of the two species are markedly different. C. citricola has but one 

 generation in a year, while C. hesperidum has three or four over-lapping 

 generations. From August to March all living individuals of the former 

 species are of one size, while there are two distinct sizes of the latter. 

 C. citricola is oviparous, while C. hesperidum is ovoviviparous. The 

 host- plants of C. hesperidum cover a wide range ; those of C. citricola 

 include all varieties of Citrus, Celtis occidentalis (hackberry), Rhamnus 

 crocea (buckthorn), Punica granatum (pomegranate), Solanum douglassi 

 (night- shade), Juglans regia (English walnut), and Ulmus americana 

 (elm). Parasites reared from both species of Coccus include Cocco- 

 phagus lecmiii, C. lunulatus, and Ap)hycus luteolus. Microterys flavus 

 is parasitic upon hesperidum, but apparently not upon citricola ; the 

 opposite is the case with Coccophagus jiavoscutellum. 



